Support CredentialsProvider for SSH connections

When setting up an SSH connection, use the caller supplied
CredentialsProvider, if one has been given to the Transport
or was defined as the default.

The CredentialsProvider is re-wrapped as a JSch UserInfo,
allowing the connection to use this for user interactive
prompts.  This give a unified API for authentication on
any transport type.

Change-Id: Id3b4cf5bfd27a23207cdfb188bae3b78e71e02c0
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

org.eclipse.jgit/src/org/eclipse/jgit/transport/CredentialItem.java

@@ -211,6 +211,60 @@ public abstract class CredentialItem {
 		}
 	}
 
+	/** An item whose value is a boolean choice, presented as Yes/No. */
+	public static class YesNoType extends CredentialItem {
+		private boolean value;
+
+		/**
+		 * Initialize a prompt for a single boolean answer.
+		 *
+		 * @param promptText
+		 *            prompt to display to the user alongside of the input
+		 *            field. Should be sufficient text to indicate what to
+		 *            supply for this item.
+		 */
+		public YesNoType(String promptText) {
+			super(promptText, false);
+		}
+
+		@Override
+		public void clear() {
+			value = false;
+		}
+
+		/** @return the current value */
+		public boolean getValue() {
+			return value;
+		}
+
+		/**
+		 * Set the new value.
+		 *
+		 * @param newValue
+		 */
+		public void setValue(boolean newValue) {
+			value = newValue;
+		}
+	}
+
+	/** An advice message presented to the user, with no response required. */
+	public static class InformationalMessage extends CredentialItem {
+		/**
+		 * Initialize an informational message.
+		 *
+		 * @param messageText
+		 *            message to display to the user.
+		 */
+		public InformationalMessage(String messageText) {
+			super(messageText, false);
+		}
+
+		@Override
+		public void clear() {
+			// Nothing to clear.
+		}
+	}
+
 	/** Prompt for a username, which is not masked on input. */
 	public static class Username extends StringType {
 		/** Initialize a new username item, with a default username prompt. */

org.eclipse.jgit/src/org/eclipse/jgit/transport/CredentialsProvider.java

@@ -80,6 +80,17 @@ public abstract class CredentialsProvider {
 		defaultProvider = p;
 	}
 
+	/**
+	 * Check if the provider is interactive with the end-user.
+	 *
+	 * An interactive provider may try to open a dialog box, or prompt for input
+	 * on the terminal, and will wait for a user response. A non-interactive
+	 * provider will either populate CredentialItems, or fail.
+	 *
+	 * @return {@code true} if the provider is interactive with the end-user.
+	 */
+	public abstract boolean isInteractive();
+
 	/**
 	 * Check if the provider can supply the necessary {@link CredentialItem}s.
 	 *

org.eclipse.jgit/src/org/eclipse/jgit/transport/CredentialsProviderUserInfo.java

@@ -0,0 +1,150 @@
+/*
+ * Copyright (C) 2010, Google Inc.
+ * and other copyright owners as documented in the project's IP log.
+ *
+ * This program and the accompanying materials are made available
+ * under the terms of the Eclipse Distribution License v1.0 which
+ * accompanies this distribution, is reproduced below, and is
+ * available at http://www.eclipse.org/org/documents/edl-v10.php
+ *
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or
+ * without modification, are permitted provided that the following
+ * conditions are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above
+ *   copyright notice, this list of conditions and the following
+ *   disclaimer in the documentation and/or other materials provided
+ *   with the distribution.
+ *
+ * - Neither the name of the Eclipse Foundation, Inc. nor the
+ *   names of its contributors may be used to endorse or promote
+ *   products derived from this software without specific prior
+ *   written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
+ * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+package org.eclipse.jgit.transport;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+
+import com.jcraft.jsch.Session;
+import com.jcraft.jsch.UIKeyboardInteractive;
+import com.jcraft.jsch.UserInfo;
+
+/** A JSch {@link UserInfo} adapter for a {@link CredentialsProvider}. */
+public class CredentialsProviderUserInfo implements UserInfo,
+		UIKeyboardInteractive {
+	private final URIish uri;
+
+	private final CredentialsProvider provider;
+
+	private String password;
+
+	private String passphrase;
+
+	/**
+	 * Wrap a CredentialsProvider to make it suitable for use with JSch.
+	 *
+	 * @param session
+	 *            the JSch session this UserInfo will support authentication on.
+	 * @param credentialsProvider
+	 *            the provider that will perform the authentication.
+	 */
+	public CredentialsProviderUserInfo(Session session,
+			CredentialsProvider credentialsProvider) {
+		this.uri = createURI(session);
+		this.provider = credentialsProvider;
+	}
+
+	private static URIish createURI(Session session) {
+		URIish uri = new URIish();
+		uri = uri.setScheme("ssh");
+		uri = uri.setUser(session.getUserName());
+		uri = uri.setHost(session.getHost());
+		uri = uri.setPort(session.getPort());
+		return uri;
+	}
+
+	public String getPassword() {
+		return password;
+	}
+
+	public String getPassphrase() {
+		return passphrase;
+	}
+
+	public boolean promptPassphrase(String msg) {
+		CredentialItem.StringType v = newPrompt(msg);
+		if (provider.get(uri, v)) {
+			passphrase = v.getValue();
+			return true;
+		} else {
+			passphrase = null;
+			return false;
+		}
+	}
+
+	public boolean promptPassword(String msg) {
+		CredentialItem.StringType v = newPrompt(msg);
+		if (provider.get(uri, v)) {
+			password = v.getValue();
+			return true;
+		} else {
+			password = null;
+			return false;
+		}
+	}
+
+	private CredentialItem.StringType newPrompt(String msg) {
+		return new CredentialItem.StringType(msg, true);
+	}
+
+	public boolean promptYesNo(String msg) {
+		CredentialItem.YesNoType v = new CredentialItem.YesNoType(msg);
+		return provider.get(uri, v) && v.getValue();
+	}
+
+	public void showMessage(String msg) {
+		provider.get(uri, new CredentialItem.InformationalMessage(msg));
+	}
+
+	public String[] promptKeyboardInteractive(String destination, String name,
+			String instruction, String[] prompt, boolean[] echo) {
+		CredentialItem.StringType[] v = new CredentialItem.StringType[prompt.length];
+		for (int i = 0; i < prompt.length; i++)
+			v[i] = new CredentialItem.StringType(prompt[i], !echo[i]);
+
+		List<CredentialItem> items = new ArrayList<CredentialItem>();
+		if (instruction != null && instruction.length() > 0)
+			items.add(new CredentialItem.InformationalMessage(instruction));
+		items.addAll(Arrays.asList(v));
+
+		if (!provider.get(uri, items))
+			return null; // cancel
+
+		String[] result = new String[v.length];
+		for (int i = 0; i < v.length; i++)
+			result[i] = v[i].getValue();
+		return result;
+	}
+}

org.eclipse.jgit/src/org/eclipse/jgit/transport/SshConfigSessionFactory.java

@@ -83,7 +83,8 @@ public abstract class SshConfigSessionFactory extends SshSessionFactory {
 
 	@Override
 	public synchronized Session getSession(String user, String pass,
-			String host, int port, FS fs) throws JSchException {
+			String host, int port, CredentialsProvider credentialsProvider,
+			FS fs) throws JSchException {
 		if (config == null)
 			config = OpenSshConfig.get(fs);
 
@@ -105,6 +106,11 @@ public abstract class SshConfigSessionFactory extends SshSessionFactory {
 		final String pauth = hc.getPreferredAuthentications();
 		if (pauth != null)
 			session.setConfig("PreferredAuthentications", pauth);
+		if (credentialsProvider != null
+				&& (!hc.isBatchMode() || !credentialsProvider.isInteractive())) {
+			session.setUserInfo(new CredentialsProviderUserInfo(session,
+					credentialsProvider));
+		}
 		configure(hc, session);
 		return session;
 	}

org.eclipse.jgit/src/org/eclipse/jgit/transport/SshSessionFactory.java

@@ -111,6 +111,8 @@ public abstract class SshSessionFactory {
 	 * @param port
 	 *            port number the server is listening for connections on. May be <=
 	 *            0 to indicate the IANA registered port of 22 should be used.
+	 * @param credentialsProvider
+	 *            provider to support authentication, may be null.
 	 * @param fs
 	 *            the file system abstraction which will be necessary to
 	 *            perform certain file system operations.
@@ -119,14 +121,16 @@ public abstract class SshSessionFactory {
 	 *             the session could not be created.
 	 */
 	public abstract Session getSession(String user, String pass, String host,
-			int port, FS fs) throws JSchException;
+			int port, CredentialsProvider credentialsProvider, FS fs)
+			throws JSchException;
 
 	/**
 	 * Close (or recycle) a session to a host.
 	 *
 	 * @param session
 	 *            a session previously obtained from this factory's
-	 *            {@link #getSession(String,String, String, int, FS)} method.s
+	 *            {@link #getSession(String,String, String, int, CredentialsProvider, FS)}
+	 *            method.
 	 */
 	public void releaseSession(final Session session) {
 		if (session.isConnected())

org.eclipse.jgit/src/org/eclipse/jgit/transport/SshTransport.java

@@ -128,7 +128,8 @@ public abstract class SshTransport extends TcpTransport {
 		final String host = uri.getHost();
 		final int port = uri.getPort();
 		try {
-			sock = sch.getSession(user, pass, host, port, local.getFS());
+			sock = sch.getSession(user, pass, host, port,
+					getCredentialsProvider(), local.getFS());
 			if (!sock.isConnected())
 				sock.connect(tms);
 		} catch (JSchException je) {

org.eclipse.jgit/src/org/eclipse/jgit/transport/UsernamePasswordCredentialsProvider.java

@@ -76,6 +76,11 @@ public class UsernamePasswordCredentialsProvider extends CredentialsProvider {
 		this.password = password;
 	}
 
+	@Override
+	public boolean isInteractive() {
+		return false;
+	}
+
 	@Override
 	public boolean supports(CredentialItem... items) {
 		for (CredentialItem i : items) {